This research explores whether male risk taking emerges as a sexual display strategy in the presence of attractive women. Experiments 1 to 3 explored whether young males reported and engaged in more risk taking after viewing pictures of highly attractive females. Possible self-control mechanisms were investigated via working memory, reversal learning, and Stroop tasks. In addition, second to fourth digit ratio (2D:4D) was measured as a proxy for individual differences in testosterone. Viewing pictures of highly attractive females led to greater self-reported risk-taking. 2D:4D was found to moderate the effect on risk-taking behaviours, with increases for high, but decreases for low testosterone males. Digit ratio also moderated the effects observed on the Stroop and reversal learning tasks. Experiments 4 and 5 extended these findings to examine how power interacts with testosterone to influence risk taking and inhibitory control. As testosterone is as-sociated with the pursuit of power and status (Dabbs & Dabbs, 2000), high testoster-one individuals primed with power were expected to have little reason to disrupt the status quo and thus should be risk-avoidant. Conversely, high-testosterone individuals primed with low power were expected to use risk taking as a vehicle for pursuing po-tential gains to their status and resources. The findings from two experiments are con-sistent with these predictions. In Experiment 1, higher testosterone males (as indicated by second–fourth digit ratio) showed greater risk-taking when primed with low power. Experiment 2 replicated this effect and also showed that when primed with high power, higher testosterone males took fewer risks. The influence of power on Stroop performance was also moderated by individual differences in testosterone. Par-ticipants primed with high power showed better Stroop performance if they were lower in testosterone, whereas participants primed with low power showed better Stroop performance if they were higher in testosterone. These results suggest that greater executive control accompanies but does not underlie enhanced risk taking, caused by testosterone and power. Finally, results from a field experiment (Experiment 6) with skateboarders demon-strate that physical risk taking by young male skateboarders increases in the presence of an attractive female. This increased risk taking led to more successes but also more crash landings in front of the female observer. Mediational analyses suggest that this increase in risk taking is caused in part by elevated testosterone levels of men who performed in front of the attractive female. In addition, skateboarders’ risk taking was predicted by their performance on a reversal-learning task, reversal-learning perform-ance was disrupted by the presence of the attractive female, and the female’s presence moderated the observed relationship between risk taking and reversal learning. These results suggest that men use physical risk taking as a sexual display strategy, and they provide suggestive evidence regarding possible hormonal and neural mechanisms.

This research explores whether male risk taking emerges as a sexual display strategy in the presence of attractive women. Experiments 1 to 3 explored whether young males reported and engaged in more risk taking after viewing pictures of highly attractive females. Possible self-control mechanisms were investigated via working memory, reversal learning, and Stroop tasks. In addition, second to fourth digit ratio (2D:4D) was measured as a proxy for individual differences in testosterone. Viewing pictures of highly attractive females led to greater self-reported risk-taking. 2D:4D was found to moderate the effect on risk-taking behaviours, with increases for high, but decreases for low testosterone males. Digit ratio also moderated the effects observed on the Stroop and reversal learning tasks. Experiments 4 and 5 extended these findings to examine how power interacts with testosterone to influence risk taking and inhibitory control. As testosterone is as-sociated with the pursuit of power and status (Dabbs & Dabbs, 2000), high testoster-one individuals primed with power were expected to have little reason to disrupt the status quo and thus should be risk-avoidant. Conversely, high-testosterone individuals primed with low power were expected to use risk taking as a vehicle for pursuing po-tential gains to their status and resources. The findings from two experiments are con-sistent with these predictions. In Experiment 1, higher testosterone males (as indicated by second–fourth digit ratio) showed greater risk-taking when primed with low power. Experiment 2 replicated this effect and also showed that when primed with high power, higher testosterone males took fewer risks. The influence of power on Stroop performance was also moderated by individual differences in testosterone. Par-ticipants primed with high power showed better Stroop performance if they were lower in testosterone, whereas participants primed with low power showed better Stroop performance if they were higher in testosterone. These results suggest that greater executive control accompanies but does not underlie enhanced risk taking, caused by testosterone and power. Finally, results from a field experiment (Experiment 6) with skateboarders demon-strate that physical risk taking by young male skateboarders increases in the presence of an attractive female. This increased risk taking led to more successes but also more crash landings in front of the female observer. Mediational analyses suggest that this increase in risk taking is caused in part by elevated testosterone levels of men who performed in front of the attractive female. In addition, skateboarders’ risk taking was predicted by their performance on a reversal-learning task, reversal-learning perform-ance was disrupted by the presence of the attractive female, and the female’s presence moderated the observed relationship between risk taking and reversal learning. These results suggest that men use physical risk taking as a sexual display strategy, and they provide suggestive evidence regarding possible hormonal and neural mechanisms.

This research explores whether male risk taking emerges as a sexual display strategy in the presence of attractive women. Experiments 1 to 3 explored whether young males reported and engaged in more risk taking after viewing pictures of highly attractive females. Possible self-control mechanisms were investigated via working memory, reversal learning, and Stroop tasks. In addition, second to fourth digit ratio (2D:4D) was measured as a proxy for individual differences in testosterone. Viewing pictures of highly attractive females led to greater self-reported risk-taking. 2D:4D was found to moderate the effect on risk-taking behaviours, with increases for high, but decreases for low testosterone males. Digit ratio also moderated the effects observed on the Stroop and reversal learning tasks. Experiments 4 and 5 extended these findings to examine how power interacts with testosterone to influence risk taking and inhibitory control. As testosterone is as-sociated with the pursuit of power and status (Dabbs & Dabbs, 2000), high testoster-one individuals primed with power were expected to have little reason to disrupt the status quo and thus should be risk-avoidant. Conversely, high-testosterone individuals primed with low power were expected to use risk taking as a vehicle for pursuing po-tential gains to their status and resources. The findings from two experiments are con-sistent with these predictions. In Experiment 1, higher testosterone males (as indicated by second–fourth digit ratio) showed greater risk-taking when primed with low power. Experiment 2 replicated this effect and also showed that when primed with high power, higher testosterone males took fewer risks. The influence of power on Stroop performance was also moderated by individual differences in testosterone. Par-ticipants primed with high power showed better Stroop performance if they were lower in testosterone, whereas participants primed with low power showed better Stroop performance if they were higher in testosterone. These results suggest that greater executive control accompanies but does not underlie enhanced risk taking, caused by testosterone and power. Finally, results from a field experiment (Experiment 6) with skateboarders demon-strate that physical risk taking by young male skateboarders increases in the presence of an attractive female. This increased risk taking led to more successes but also more crash landings in front of the female observer. Mediational analyses suggest that this increase in risk taking is caused in part by elevated testosterone levels of men who performed in front of the attractive female. In addition, skateboarders’ risk taking was predicted by their performance on a reversal-learning task, reversal-learning perform-ance was disrupted by the presence of the attractive female, and the female’s presence moderated the observed relationship between risk taking and reversal learning. These results suggest that men use physical risk taking as a sexual display strategy, and they provide suggestive evidence regarding possible hormonal and neural mechanisms.

Empathy is an essential prerequisite for the development and maintenance of close interpersonal relationships. Given that older adults are particularly vulnerable to the negative consequences of loneliness and social isolation, it is surprising that few studies have assessed empathy in this group. The current programme of research addressed this gap in the literature by testing competing predictions derived from Socioemotional Selectivity Theory and the Ageing-Brain Model for age-related sparing and impairment of empathy, respectively. Study 1 compared young (N = 80) and older (N = 49) adults?? self-reported levels of cognitive and affective empathy, and engagement in social activities. It was found that although affective empathy is spared, cognitive empathy is subject to age-related decline, and this decline mediates reductions in social participation. These data therefore affirmed the importance of further investigation into the nature, causes and potential consequences of age-related differences in empathy. Since disinhibition is one mechanism contributing to difficulty taking the perspective of another, and is known to increase with age, in Study 2, behavioural measures sensitive to inhibitory failure and to cognitive empathy were administered to young (N = 36) and older (N = 33) adults. One of the measures of cognitive empathy directly manipulated inhibitory demands, involving either high or low levels of self-perspective inhibition. The results indicated that older adults were selectively impaired on the high-inhibition condition, with cognitive disinhibition mediating this association. Study 2 therefore provided important evidence relating to one potential mechanism that contributes to age-related difficulties in perspective-taking. Studies 3 and 4 provided the first behavioural assessments of age-related differences in affective empathy by using electromyography to index facial expression mimicry. Study 3 found that young (N = 35) and older (N = 35) adults?? demonstrate comparable mimicry of anger, but older adults?? initial (i.e., implicit) reactions were associated with reduced anger recognition. Thus, to test the possibility that despite explicit recognition difficulties, implicit processing of facial expressions may be preserved in older adulthood, Study 4 compared young (N = 46) and older (N = 40) adults?? mimicry responses to subliminally presented angry and happy facial expressions. As predicted, the two groups demonstrated commensurate subconscious mimicry of these expressions. Taken together, these studies indicate that separate components of empathy are differentially affected by healthy adult ageing. Implications for competing perspectives of socioemotional functioning in older adulthood are discussed.

In the present work, we examine how the cognitive system responds to complex environments. It has been proposed that executive control, which is responsible for orchestrating high-level behavior in such environments, operates according to different broad processing modes, one geared towards stability and focus (“maintenance”), and the other that’s open to environmental influence (“updating”). Aging work has proposed that this latter mode is over-represented in older age, leading to deficits in many, but not all cognitive domains. Across three studies, we sought to identify the dynamics of the updating state in particular, and how those dynamics are shifted in older age. In Chapter 2, we used a paradigm designed specifically to enforce maintenance and updating states with an age-comparative sample, and found that older adults show increased behavioral costs (reaction times) and distractibility (distractor fixations) consistent with being “chronic updaters”. In Chapter 3 we probed the updating state by examining spontaneous fixations towards irrelevant cues, allowing us to identify how it occurs both in response to the task context, and independently from it. We found that older adults were more sensitive to global changes in the task context (single versus mixed-task blocks), but also showed a stronger tendency to update independently from the task. Younger adults, by contrast, were more prone to update in response to transient task events. In Chapter 4, we lay the groundwork to address these questions with neuroimaging, using machine learning to extract information regarding the task context (task set, targets, distractors, response-selection) in a task-switching paradigm on a trial-by-trial and moment-by-moment level. This opens the door for more directly measuring neural signatures of updating and gives a more high-fidelity measure to examine the dynamics of how and when it occurs. Together, this work provides some insight into the dynamics and age-differences involved in global processing states, which heretofore have been under-investigated in the literature. Additionally, we provide important analytic and methodological advancements for extending this work in the future.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / During the execution of the foundations of a building, commonly checks load capacity employing specific methods which vary depending on the type of stake, which is called evaluation of foundation performance. To stakes control is, generally made based on load test. This paper proposes a formulation for empirical prediction type of the root cuttings carrying capacity obtained by some variables monitored during their execution using a speedometer digital. For that were made slow static load tests in three root cuttings monitored at 350 and 410 mm. Several combinations of the parts of the peak load capacity and the side and monitored variables were tested, using computer programs Excel and Maple. It was later sought an expression for predicting the tensile strength of the tested cuttings as a function of the variables monitored, according to relations of type polynomial, exponential, logarithmic and combination linear, with reference to the value obtained according to the method of the ABNT NBR 6122: 2010. It was found that there is a correlation between the load and the variables monitored. The variables that best fit the correlation were spin and speed advance. The results obtained with the expression proposed were consistent with the values reference to the tested cuttings. The method of Lizzi (1982) presented estimates more consistent with the results obtained in the form proposed that correlates capacity load and variables involved in enforcement proceedings. / RESUMO Durante a execuÃÃo das fundaÃÃes de uma edificaÃÃo, comumente se verifica a capacidade de carga empregando-se mÃtodos especÃficos que variam de acordo com o tipo de estaca, o que à denominado avaliaÃÃo de desempenho da fundaÃÃo. Para estacas o controle Ã, em geral, feito com base em de prova de carga. Este trabalho propÃe uma formulaÃÃo empÃrica para previsÃo da capacidade de carga de estacas tipo raiz, obtidas por meio de algumas variÃveis monitoradas durante a execuÃÃo das mesmas utilizando um velocÃmetro digital. Para isso foram realizadas provas de carga estÃticas lentas em trÃs estacas raiz monitoradas, com diÃmetros de 350 e 410 mm. Diversas combinaÃÃes entre as parcelas da capacidade de carga de ponta e lateral e as variÃveis monitoradas foram testadas, utilizando-se os programas de computador Excel e Maple. Posteriormente foi buscada uma expressÃo para a previsÃo da carga de ruptura das estacas ensaiadas, como uma funÃÃo das variÃveis monitoradas, segundo relaÃÃes do tipo polinomial, exponencial, logarÃtmica e combinaÃÃo linear, tendo como referÃncia o valor obtido de acordo com o mÃtodo da Norma ABNT NBR 6122:2010. Foi verificado que hà correlaÃÃo entre a capacidade de carga e as variÃveis monitoradas. As variÃveis que melhor se ajustaram na correlaÃÃo foram: rotaÃÃo e velocidade de avanÃo. Os resultados obtidos pela expressÃo proposta foram concordantes com os valores de referÃncia para as estacas ensaiadas. O mÃtodo de Lizzi (1982) apresentou estimativas mais concordantes com os resultados obtidos na formulaÃÃo proposta que correlaciona capacidade de carga e variÃveis envolvidas no processo executivo.

In this dissertation, the traditional dichotic listening paradigm was integrated with the notion of working memory capacity (WMC) to explore the cognitive mechanism of bilingual speech comprehension at the passage level. A bilingual dichotic listening (BDL) task was developed and administered to investigate characteristics of bilingual listening comprehension, which include semantic relatedness, unattended language, ear preference, auditory attentional control, executive control, voluntary note-taking, and language switching. The central concept of the BDL paradigm is that the auditory stimuli are presented in the bilinguals’ two languages and their attention is directed to one of their ears while they have to overcome cognitive and linguistic conflicts caused by information in the other ear. Different experimental manipulations were employed in the BDL task to examine the characteristics of bilingual listening comprehension. The bilingual population examined was Japanese- English bilinguals with relatively high second language (L2) proficiency and WMC. Seven experiments and seven cross-experimental comparisons are reported. Experiment 1 employed the BDL task with pairs of passages that had different semantic relationships (i.e., related or unrelated) and were heard in different languages (i.e., L1 or L2). The semantically related passages were found to interfere with comprehension of the attended passage more than the semantically unrelated passages, whether the attended and unattended languages were the same or different. Contrary to the theories of bilingual language control, unattended L1 was found to enhance comprehension of the attended passage, regardless of semantic relationships and language it was heard in. L2 proficiency and WMC served as good predictors of resolution of the cognitive and linguistic conflicts. The BDL task is suggested to serve as an experimental paradigm to explore executive control and language control in bilingual speech comprehension. Experiment 2 was conducted to investigate language lateralisation (i.e., ear preference) on bilingual speech comprehension, hence, the participants in Experiment 1 used their preferred ear, whereas participants in Experiment 2 used their non-preferred ear, whether it was left or right, in the BDL task. Comprehension was better through the preferred ear, indicating that there is a favourable ear-to-hemisphere route for understanding bilinguals’ two languages. Most of the participants were found to be left-lateralised (i.e., right-eared) and some to be right-lateralised (i.e., left-eared) presumably depending on their L2 proficiency and WMC. Experiment 3 was concerned with auditory attentional control, and explored whether there would be a right-ear advantage (REA). The participants indicated an REA whether the attended and unattended languages were L1 or L2. When they listened to Japanese in the left ear, they found it more difficult to suppress Japanese in the right ear than English. WMC was not required as much as expected for auditory attentional control probably because the passages in Experiment 3 did not yield as much semantic competition as those in Experiment 1. L2 proficiency was crucial for resolving within- and between-language competition in each ear. Experiments 4, 5, and 6 were replications of Experiments 1, 2 and 3, but these latter experiments considered the effect of note-taking that is commonly performed in everyday listening situations. Note-taking contributed to better performance and clearer understanding of the role of WMC in bilingual speech comprehension. A cross-experimental analysis between Experiments 1, 2, 4, and 5 revealed not only a facilitatory role of note-taking in bilingual listening comprehension in general, but also a hampering role when listening through the preferred ear. Experiment 7 addressed the effect of predictability of language switching by presenting L1 and L2 in a systematic order while switching attention between ears and comparing the result with that of Experiment 6 where language switching was unpredictable. The effect of predictability of language switching was different between ears. When language switches were predictable, higher comprehension was observed in the left ear than the right ear, and when language switches were unpredictable, higher comprehension was observed in the right ear than the left ear, thereby suggesting a mechanism of asymmetrical language control. WMC was more related to processing of predictable language switches than that of unpredictable language switches. The dissertation ends with discussions of the implications from the seven BDL experiments and possible applications, along with experimental techniques from other relevant disciplines that might be used in future research to yield additional insight into how bilingual listeners sustain their listening performance in their two languages in the real-life situations.

Experimental studies on willpower confirm the Strength Model of Self-Control, which claims that willpower depends on limited physiological resources. Exercising willpower depletes these resources, which impairs further exercises of willpower. This phenomenon is called “ego-depletion.” As a result, depleting these resources impairs further exercises of executive control. My thesis argues that this phenomenon has two important philosophical consequences: First, ego-depletion provides evidence against the Humean approach to motivation, according to which people always act according to their strongest desires. Second, people suffering from ego-depletion are not fully responsible for failures of self-control.

Les humains doivent sans cesse s’adapter à des environnements incertains, changeants et ouverts. Pour ce faire, il est nécessaire d’explorer, d’ajuster et d’exploiter plusieurs task-sets, c’est-à-dire des associations sensorimotrices flexibles entre des stimuli, des actions et des résultats. Collins et Kœchlin ont proposé un modèle computationnel qui contrôle la création, l’apprentissage, le stockage, la récupération et la sélection de tels task-sets pour guider le comportement (Collins & Kœchlin, 2012, PloS biology). Le modèle met à jour les fiabilités d’un ensemble de task-sets, c’est-à-dire leur capacité à prédire correctement les conséquences des actions. Cette mise à jour des fiabilités est réalisée par inférence bayésienne en intégrant les résultats des actions et l’information contextuelle. Elle permet d’arbitrer entre l’exploitation du task-set le plus fiable et l’exploration de nouveaux task-sets. En l’absence d’information contextuelle, la fiabilité des task-sets appris est maintenue et mise à jour dans le cortex frontopolaire (Donoso, Collins & Kœchlin, Science, 2014). Ce travail de thèse a pour but d’élucider les mécanismes neuraux permettant le monitorage et la récupération de task-sets stockés en mémoire, que ce soit selon les indices contextuels ou les résultats des actions. Pour ce faire, nous avons élaboré une expérience d’IRM fonctionnelle dans laquelle des sujets sains doivent apprendre, par essais et erreurs, plusieurs task-sets associés à divers indices contextuels, puis réutiliser les task-sets appris. Les conditions expérimentales varient de façon non prédictible de telle sorte que : (i) des task-sets précédemment appris doivent être réutilisés soit avec le même indice contextuel, soit avec un indice contextuel nouveau ; (ii) de nouveaux task-sets doivent être appris soit avec de nouveaux indices contextuels, soit avec des indices connus. Les résultats comportementaux montrent que les sujets apprennent, maintiennent, mettent à jour et réutilisent un répertoire grandissant de task-sets tel que le prédit le modèle computationnel. Plus précisément : (i) les indices contextuels connus sont utilisés de façon proactive (avant l’exécution d’une action) pour sélectionner le task-set correspondant ; (ii) lorsque les indices contextuels sont inconnus, les sujets sélectionnent le task-set de façon réactive, selon les résultats des actions. Les résultats d’imagerie révèlent que la fiabilité des task-sets est mise à jour dans le cortex frontopolaire et le cortex préfrontal dorso-latéral. De plus, le cortex préfrontal latéral est impliqué dans le processus de sélection proactif et réactif. Cependant, les récupérations proactives et réactives dépendent de réseaux distincts : (i) d’une part la récupération proactive repose sur un réseau ventral qui inclut le cortex préfrontal ventro-médian, le striatum et l’hippocampe ;(ii) d’autre part, la récupération réactive repose sur un réseau frontal incluant notamment le cortex frontopolaire. / Humans need to adapt to uncertain, changing, and open-ended environ- ments. In such situations, decision-making involves exploring, adjusting and ex- ploiting multiple task-sets – defined as flexible sensorimotor mappings associating stimuli, actions, and expected outcomes. Collins and Kœchlin proposed a computational model that controls the crea- tion, learning, storage, retrieval, and selection of such task-sets for driving action (Collins & Kœchlin, 2012, PloS biology). The model monitors the reliability of a collection of concurrent task-sets - i.e., the ability of alternative task-sets to correctly predict action outcomes. Task-set reliability is updated in a Bayesian manner according to outcomes and contextual information and arbitrates between exploiting the most reliable task- set or exploring new ones to drive action. It has recently been shown that, without contextual information, the reliability of alternative learned task-sets is monito- red in frontopolar cortex (Donoso, Collins & Kœchlin, Science, 2014). The goal of this study is to investigate the neural mechanisms that subserve the monitoring and retrieval of stored task-sets according to both contextual cues and action outcomes. We designed an fMRI experiment requiring healthy human subjects to learn by trials and errors and to switch between multiple task-sets associated with va- rious contextual cues. Experimental conditions varied unpredictably such that: (i) previously learned task-sets re-occurred with either the same or new contextual cues, (ii) new task-sets that needed to be learned occurred with new cues or pre- viously encountered ones. Behavioral results and model fits show that subjects learned, monitored and switched across an expanding repertoire of task-sets as predicted by the compu- tational model. More specifically : (i) Known contextual cues were used proactively (before performing any action) to select the corresponding task-set ; (ii) When previously learned task-sets re-occurred with unknown contextual cues, subjects selected the stored task-set reactively based on action outcomes. Model-based fMRI results revealed that task-set reliability is updated in the frontopolar cortex and the lateral prefrontal cortex. Moreover, lateral prefrontal cortex is engaged in the selection process in both cases. However distinct networks are involved depending on whether the retrieval is cue or outcome-based: (i) on the one hand, proactive retrieval relies on a ventral pathway including ventromedial prefrontal cortex, striatum and bilateral hippocampus ;(ii) on the other hand, reactive retrieval relies on a frontal network including frontopolar cortex.

Working memory (WM) capacity – the capacity to maintain and manipulate information in mind – plays an essential role in high-level cognitive functions. An important determinant of WM capacity is the ability to resolve interference of previously encoded but no longer relevant information (proactive interference: PI). Four different mechanisms of PI resolution involving binding and inhibition have been proposed in the literature, although debate continues regarding their role. Braver et al. (2007) introduced an important distinction in the PI resolution literature, proposing two general types of PI control mechanisms that occur at different time points: proactive control (involves preparation in advance of the interference) and reactive control (occurs after interference occurs). This thesis proposed that among these four functions involving binding and inhibition, item inhibition and binding could be involved in proactive control, while familiarity inhibition and episodic inhibition could be involved in reactive control. The question is which mechanism in each pair is indeed involved in proactive control and reactive control respectively, and how these proactive control and reactive control mechanisms work together to resolve PI. In addition, do these mechanisms play a role in the relationship between PI resolution and WM? In an individual differences study, individuals’ ability to resolve PI was assessed in memory tasks, with two versions of each that encouraged the use of either proactive or reactive control. In addition, measures were obtained of individuals’ ability of binding and inhibition in tasks that had minimal memory demands. Regression analyses showed contributions of binding and inhibition to PI resolution and WM. Moreover, these functions are responsible for the correlation between PI resolution and WM. In a neuroimaging study, the neural basis of proactive control was examined by comparing two memory tasks that differed in their demand on binding and inhibition. In addition, the brain regions engaged in reactive control was examined by contrasting trials involving interference or not. The thesis showed that item inhibition carried out by the left inferior frontal cortex (IFC) is involved in proactive control while episodic inhibition carried out by the left IFC and the posterior parietal cortex is involved in reactive control.